MODIS-Terra Reprocessing 2010.0
In November 2010, the NASA Ocean Biology Processing Group initiated an ocean color reprocessing of the full MODIS-Terra mission. The motivation for this reprocessing was to 1) improve the instrument calibration, 2) incorporate the latest processing algorithms and product formats that were already in use for MODIS-Aqua and SeaWiFS, and 3) to extend the MODIS-Terra ocean color time-series back to the beginning of the mission. This is the first complete mission processing of the MODIS-Terra data set performed by the NASA Ocean Biology Processing Group.
2.1. Instrument Calibration
The issues and limitations of the MODIS-Terra instrument calibration have been well documented (Franz et al., 2008). The methods applied to derive the calibration adjustments for the 2010.0 reprocessing have been described in Kwiatkowska et al., 2008. Radiometric gain and polarization corrections were derived using 1) SeaWiFS data as truth fields for bands 8-12 (412nm, 443nm, 488nm, 531nm, 547nm) and 2) MODIS Aqua data as truth fields for bands 13-14 (667nm, 678nm). The corrections for the land bands 3-5 (469nm, 555nm, 645nm) were spectrally interpolated from the bracketing ocean bands.
2.2. Processing Algorithms
This is the first complete mission processing of the MODIS-Terra data set performed by the Ocean Biology Processing Group. Prior to this time, the algorithms employed for the forward stream processing of MODIS-Terra were based on the R2005.1 processing developed for MODIS-Aqua. For this reprocessing (R2010.0), the algorithms changes associated with MODIS-Aqua R2009.1 were employed.
The global trends in Rrs and derived products for the ocean bands are in excellent agreement with those of the SeaWiFS and MODIS Aqua trends. The Rrs of the land bands appear to have different trends from the ocean bands (469nm increases too much, 555nm decreases too much), which suggests that the approach to derive the corrections for the land bands needs to be improved. A detailed analysis of the results is presented in Meister et al., 2011. The temporal trends of the global averages can be assessed following this link (TT21 = MODIS Terra data, AT66 = MODIS Aqua data).
E.J. Kwiatkowska, B.A. Franz, G. Meister, C.R. McClain, X. Xiong (2008). Cross-Calibration of ocean color bands from Moderate Resolution Imaging Spectroradiometer on Terra platform. Applied Optics, 47: (36) 6796-6810.
Franz, B.A., E.J. Kwiatkowska, G. Meister, and C.R. McClain (2008). Moderate Resolution Imaging Spectroradiometer on Terra: limitations for ocean color applications, J. Appl. Rem. Sens., 2, 023525.
Meister, G., E.J. Kwiatkowska, B.A. Franz, F.S. Patt, G.C. Feldman, C.R. McClain (2005). Moderate-Resolution Imaging Spectroradiometer ocean color polarization correction. Applied Optics, 44: (26) 5524-5535.
- Meister, G., B.A. Franz (2011). Adjustments to the MODIS Terra radiometric calibration and polarization sensitivity in the 2010 reprocessing. Proc. of SPIE Vol. 8153, 815308.